E. Loomis—Reduction of Barometric Observations. 7 
In order to deduce from these observations the most probable, 
value of the mean temperature of the air column I proceeded as 
follows: : ; 
I multiplied the half sum of the temperatures observed at the 
first and second stations by the difference of elevation between 
the two stations; I multiplied the half sum of the temperatures 
observed at the second and third stations by their difference of 
elevation. I proceeded in like manner with the third and 
fourth stations, and also with the fourth and fifth. I then 
divided the sum of these four products by the difference of 
level between the first and fifth stations and regarded the quo- 
tient as representing the mean temperature of the air column. 
The difference between this result and the half sum of the tem- 
peratures at the first and fifth stations is given in column 
seventh, where the + sign indicates that the mean temperature 
of the aircolumn is greater than the half sum of the tempera- 
tures at the upper and lower stations. I proceeded in the same 
manner with the observations at 4.35 Pp. M. and 11 P. M. | 
Taste IV.— Change of temperature with elevation. 
135 A. M. 4°35 P.M. ll P.M, 
: l 
5/5553 4058/2898) 134 | Diff. ||6285/5553|4058 2898) 134] Diff. |6285 5553 4058 2898) 
51 |61°614+1°0||42 |48°5 155-5 63°5 |74°0 | +2°°1||/37 
: 35°5 143-5 156°0|—1°5 |135 |42°5 147 56 |60°4/+4+3°6//29 
: ; 
6 {63 . (544/141-8142 [445/49 (58 |57°2|+2°9 1/37 
49°5 154°5 '55°6 | + 2°8 |143 55 |61 |59°6}+5°0//38 
445 151-5 |62°0|—1°0 |135 (3775/43 49 |54°8)+41°2)/35 
42°5 |48°5 (56°2/+1-1 ||40 (50°65 (56 5 166°6 | +4°5 [1/36 
49°5 150 9°4140°6 1148 (56°5 64°5 (69°5 |T1°8 | +.5°4)/41 
{58 |60°6/+3°6 1/53 |62 |70 69°8 | + 6°7 ||47 
6 (59°65 /63°0;/4+1°8 145 j47 '54 (63 |79°2|—1°41/39 
40°5 |47 ~—1°6 1133 |37. |4£ [51°56 [67-6 | —0°6 ||32 
‘152 |62°41+0°5 ||44 15 6 61 (67°83 | +3°6 1/38 
49 |48°5160°6/+1-0 1144 [4775/59 (58 (62°2}/+3°3|/41 
52°5 167 |61°2|+2°5 |l47 (50° (58 (64 |70°6/+1-9 1/46 
65 (71°6|+1°4 |/51 156 77° | +271 |\42 
50 |64°2;|—1-5 |i37 (45°65 154 (66 |72°-41/+1°5|/30 
47 |61°6|—1-0 ||44 (52 (585/64 |66°6/)+4°7 |/44 
6 |62 0/+2°3 1153 (58 (67 (68°5|71-0 /+3°9 |/63 
53°5 |60°5 |69°0| 0-0 1149 [49 (56 (63:5 |79°8 —42°4//36 
50 |62°2] 0:0 1/34 (34:5 42 |49°5 |64:2 |—1°61/32 
46 |60°0 —1:9 1/36 (39 (41 6 (6774)4+04)/34 
52 4:5 |70°4 | + 
8 
52°5 
4” 
33 
se 
165, 
169 
684/+1°5 (55 (62°5 715 |73 [176 | +44)/48 
71°2|—0°8 {157 (65°5 |73 [75-5 (80-4 | +4°4 1/50. 
71°38 |—O-2 |155 74 |78°6|4+5°0|/51 - 
75°8|—1'4 |/51 [57 (63 |T1°5|T88) +2547 |: 
72°4)/—18 |/58 [665 71 (78 |77'8 +52 - 
eS oe 
69°81 +2°8 1155 156°5 164 70-5 |74-6 
